The disclosure of U.S. Provisional Application No. 61/491,072, filed May 27, 2011, is hereby incorporated herein in its entirety by reference.
Sickles typically including cutter bars supporting a row of knives, have been used to cut plants, including, but not limited to, hay, grasses, small grains and the like, for many years.
The knives are composed of a plurality of knife or sickle sections which are mounted in side by side relation forming an elongate metal knife assembly. The elongate knife assembly is normally supported so as to slide longitudinally along an elongate stationary bar that has forwardly projecting, spaced apart guards bolted to a structural beam or knife back. The knife assembly moves back and forth in a reciprocating movement to move the knives relative to the guards so that the leading knife edges of the knives cross over the guards or through slots in the guards. This produces a shearing or cutting action which severs plant stems and stalks or other material captured between the knives and the guards.
In a harvesting machine, such as a combine or windrower, the knife assembly and stationary bar are typically supported in connection with a cutting head or header, and are oriented so as to extend sidewardly along a forward edge portion of structure such as a floor or pan of the header, hereinafter sometimes referred to generally as the floor. The floor or pan defines the lower periphery of a cut crop or plant flow area, which can include conveying apparatus, such as one or more augers or belts, operable in cooperation with a reel in machines so equipped, for conveying the cut plant material and crops, for instance, to a feeder inlet of a combine or windrow forming apparatus of a windrower.
Historically, many known sickle drive mechanisms have been located on the side end of the sickle, and connect to the knife assemblies utilizing connecting rods or Pitman arms, such as illustrated in Wanamaker, U.S. Pat. No. 1,622,299, issued Mar. 29, 1927, and Boyer, U.S. Pat. No. 2,332,840, issued Oct. 26, 1943. An observed shortcoming of these older drives, however, is that the drive rods or arms are obtrusively positioned in the cut plant flow area. The ball joints are advantageous as they accommodate misalignments of the knife assemblies relative to the stationary support structure, but they are inefficient for directing the motive power or drive forces in the desired direction longitudinally along the knife assemblies, that is, sidewardly along the length of the sickle. The referenced constructions also provided little or no protection from infiltration of dirt, dust and the like into interfaces between relatively moving parts, so as to be subject to accelerated wear and reduced service life.
More recent known side located sickle drives are less obtrusive and connect to the end of the knife assembly with a connection that better directs the motive power longitudinally along the knife assemblies. Reference in this regard, Regier et al., U.S. Pat. No. 7,121,074 B1 issued Oct. 17, 2006. An observed advantage of this drive it is that it utilizes epicyclical motion translated to the sideward reciprocating motion by connecting components that allow motion in one plane only, as opposed to the multiple plane motion afforded by the ball joints of the older drives, while allowing for or accommodating slight misalignment of the knife assemblies in the stationary supporting structure, the stationary bar. Also, in the Regier et al. construction, the connecting components most likely to be subject to substantial wear, namely, a pin joint, are replaceable, however, the pin joint appears to lack protection from infiltration of dirt, dust, and the like.
Other more recent sickle drives are adapted to be located in or below the floor or pan of a header or plant cutting machine, as shown in Priepke U.S. Pat. Nos. 7,810,304; 7,805,919; 7,730,709; 7,520,118; and 7,401,458, and Bich U.S. Pat. No. 8,011,272. These drives are compact, and provide an efficient manner of translating epicyclic motion to side to side sickle motion such that the motive forces are directed substantially longitudinally along the knife assemblies. However, these drives utilize knife arms that attach to the sickle knife assemblies with a rigid connection, which does not accommodate or adjust for variances in the vertical distance between the knife assemblies and the drive that can be present as a result of wear, manufacturing and assembly tolerances, and the like. The knife arms of these drives also lack accommodations for misalignments of the knife assembly relative to the fixed support structure, e.g., the stationary bar or knife back.
Reference also Bich et al. U.S. Pat. No. 8,151,547 which discloses a knife arm assembly, configured for attachment to a center drive, which suffers from some of the above referenced shortcomings, include an upwardly facing seal, and a knife head requiring an intermediary member for attachment to the knife, and removal and replacement of the knife pin of which connecting the knife head to the knife arm requires removal of the knife head.
Additionally, in the instances of both the Regier et al. and Priepke types of drives, and the knife head and arm assembly of Bich et al. U.S. Pat. No. 8,151,547, vertical misalignment between the output elements of the drive and the knife assemblies can occur, and if not eliminated or compensated for, can result in accelerated wear, excessive binding, rubbing, and increased power consumption. For instance, as the knife assemblies and supporting structure wear as a result of use, particularly the underside of the knife assemblies and associated support structure, the knives will have a tendency to gradually lower within the stationary support structure, but if they are not allowed to do so in the vicinity of the connection to the driving knife arm, additional stress will be created in the knife arm and head assembly. A known remedy for this problem is to shim or otherwise adjust or compensate for the wear, and if this in not properly done, it can result in the binding and increased wear and power consumption. Also, when a worn knife assembly is replaced by a new one, the new knife assembly may be thicker or otherwise different, and require new adjustment or shimming. Such height compensations, shimming, etc., as well as replacement of components, are time and productivity consuming, and thus can be particularly undesirable during plant cutting and harvesting operations when time is of the essence.
Thus, what is sought is apparatus for connection of a sickle drive to the knife assembly of a sickle which provides good power transmission, ease of removal, service and replacement, can have a vertical self-adjusting capability, and one or more of the other features, while overcoming one or more of the shortcomings and limitations, set forth above.